Pump having discharge baffle means

ABSTRACT

Pumps of the type comprising at least one rotor provided with peripheral rotor pockets, wherein baffle means cause the pumping chamber outlet to, in the rotary direction of the rotation of the rotor, include a leading portion dimensioned to open to only a part of the length of each rotor pocket followed by a trailing portion dimensioned to open to a longer length of each rotor pocket.

mte States Paten 11 1 1111 3,746,482 Luthl 1 July 17, 1973 1 PUMP HAVING DISCHARGE BAFFLE 1,021,180 3/1912 Clifton 418/206 MEANS FOREIGN PATENTS OR APPLICATIONS 1751 lnvemori 05cm" Luthi, Nashua NH 600,971 7/1934 Germany 418/206 73 Assigneez Improved Machinery Inc. Nashua, 925,906 3/l955 Germany 418/206 I Prima/y Examiner-Clarence R. Gordon [22] Filed 1971 Attorney-F. S. Troidl and Robert R. Paquin [21] Appl. No.: 186,864

[57] ABSTRACT [52] US. Cl. 418/201, 418/206 P f h l 51 1111.0. FOlc 1/24 F04C 1/14 F040 17/16 e Y compr'smg at east One 1 [58] m ch 418/19! 195 201 vided with peripheral rotor pockets, wherein baffle 0 ar 4! means cause the pumping chamber outlet to, in the re tary direction of the rotation of the rotor, include a leading portion dimensioned to open to only a part of [56] References Cited the length of each rotor pocket followed by a trailing UNITED STATES PATENTS portion dimensioned to open to a longer length of each 2,480.8 l8 8/1949 Whitfield 1. 418/201 rotor pocket 2,531,726 11/1950 Durdin r 1 1 418/206 1 1.670.681 5/1928 Haas 418/195 16 Claims, 8 Drawing; Figures PUMP HAVING DISCHARGE BAFFLE MEANS The present invention relates generally to pumps and more particularly to pumps of the type including one or more rotors provided with peripheral rotor pockets.

Throughout the operation of pumps of this type, the pump rotor or rotors are normally continuously rotatably driven at a constant, relatively high speed sufficient to accomodate the highest capacities or high capacity surges that the pumps are expected encounter. The operation of conventional pumps of this type at or near their highest capacities generally is satisfactory; however, during operation at normal or other flow rates substantially lower than their highest capacities, these conventional pumps are subject to heavy vibration and the production of loud, hammering-type noise. It is believed that such difficulties with conventional pumps operating at lower'flow rates arise as the rotor pockets, only partially filled due to the high speed of the rotor rotation, initially open to the pumping chamber outlet and the thereto connected discharge conduit along their entire lengths, thereby causing sudden backfilling of the rotor pockets from the discharge conduit and resultant momentary pressure drop in the discharge conduit and dorresponding pressure rise in the rotor pockets.

An object of the present invention is to provide a new and improved pump of the aforedescribed type which is particularly constructed and arranged to substantially minimize the beforementioned vibration and hammering-type noise.

Another object of the invention is to provide a new and improved pump of the type set forth which is particularly constructed and arranged to substantially minimize said vibration and noise in a relatively simple and economical, although highly efficient, manner.

Another object is to provide a new and improved pump of the type set forth which is particularly constructed and arranged to cause the rotor pockets to initially open to the pumping chamber outlet along only minor parts of their lengths.

Another object is to provide a new and improved pump of the type set forth which is particularly constructed and arranged to provide gradual or progressive opening of said pockets to the pumping chamber outlet.

Another object is to provide a new and improved pump of the type set forth which is particularly constructed and arranged to delay opening of the rotor pockets to the pumping chamber outlet until displacement of material from the pockets is commenced.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings wherein several preferred forms of the invention have been given by way of illustration only.

In accordance with the invention, a pump may comprise a housing containing a pumping chamber having an inlet and an outlet, rotor means in thepumping chamber provided with a plurality of peripheral rotor pockets and rotatable in a predetermined rotary direction to cause the rotor pockets to be opened to the inlet and the outlet, alternately, and baffle means causing the outlet to,in said predeten'nined rotary direction, include a leading end portion centrally of the rotor pockets dimensioned to open to only a part of the length of each rotor pocket followed by a trailing portion dimenv sioned to open to a longer length of each rotor pocket.

Referring to the drawings:

FIG. 1 is an elevational sectional view of one form of pump embodying the invention;

FIG. 2 is an enlarged, elevational sectional view taken on Line 2-2 of FIG. 1, looking in the direction of the arrows, showing the baffle means and pumping chamber outlet of the pump illustrated in FIG. ll;

FIG. 3 is a view generally similar to that of FIG. 2, but illustrating a modified form of the baffle means and outlet;

FIG. 4 is an elevational sectional view of another form of pump embodying the invention, taken through the center of the baffle means of the pump;

FIG. 5 is a fragmentary, elevational sectional view generally similar to FIG. 4, but taken through a side portion of the baffle means;

FIG. 6 is an elevational sectional view taken on Line 66 of FIG. 4, looking in the direction of the arrows, showing the baffle means and pumping chamber outlet of the pump of FIGS. 4 and 5; and

FIGS. 7 and 8 are views generally similar to FIG. 6, but illustrating modified forms of the baffle means and outlet.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, FIGS. 1 and 2 illustrate an embodiment of the invention in the form of a pump 10 which, generally considered, is of the character described in my co-pending US. Pat. Application Ser. No. 68,866, filed Sept. 2, 1970, now US. Pat. No. 3,708,249 granted Jan. 2, 1973, and assigned to the assignee of the present invention. The pump 10 comprises a pump housing or casing 12 containing a pump ing chamber 14 having therein a rotor 16 which, throughout the pump operation, is continuously rotatably driven about its longitudinal axis in the rotary direction schematically depicted by the arrow shown thereon in FIG. I. The rotor 16 includes a plurality of identical, peripheral rotor pockets or grooves 18 which extend generally spirally around the rotor longitudinal axis and along their sides are bounded by the side walls 20 of generally spiral land portions 22 of the rotor 16. The rotor pockets l8 longitudinally extend uninterrupted throughout the major portion of the length of the rotor 16 but, as shown in FIG. 2, are at their ends spaced inwardly from the ends of the rotor 16 by annular land portions 24 of the latter.

The casing 12 contains a supply-chamber 26 communicating with one side (the left-hand side, as viewed in FIG. 1) of the pumping chamber 14 through the pumping chamber inlet which is designated generally as 28. The inlet 28 extends the full length of the rotor pockets 18 to insure satisfactory feed of material from the supply chamber 26; and throughout the operation of pump 10 the material to be pumped is normally continuously supplied to the supply chamber through the material inlet 30. The supply chamber 26 contains a feed screw 32, constructed such that its rotation causes the material in the supply chamber 26 to be fed through the pumping chamber inlet 28, which during the operation of the pump 10 is rotatably driven to so supply the material. The side of the pumping chamber I4 opposite from the inlet 28 is provided with the pumping cham ber outlet 34 which connects the pumping chamber 14 with a discharge conduit 36, in turn, communicating with conventional piping (not shown) arranged to direct the pumped material to the desired location.

The pump also comprises a disc 38 mounted for rotation about an axis which is transverse to the longitudinal axis of the rotor 16 and above the latter axis. The disc 38 includes a plurality of disc lobes 40 which project outwardly from its periphery at spaced locations therearound and are sealingly received in the rotor pockets 18 adjacent to the upper side of the rotor 16 with the generally spiral rotor lands 22 sealingly received in the spaces between the disc lobes 40. As illustrated, the disc 38 is fixedly mounted on a co-axial shaft 42, also carrying the feed screw 32, which is rotatably driven in timed relationship with the rotor 16 by gear means including the gear 44.

Throughout the operation of the pump 10, the rotation of the rotor 16 causes each rotor pocket 18 to be open to the pumping chamber inlet 28 and the pumping chamber outlet 34, alternately. Each rotor pocket 18 received material from the supply chamber 26 through the pumping chamber inlet 28 and contains such received material until the disc lobes 40 discharge it through the pumping chamber outlet 34 to the discharge conduit 36.

In accordance with the present invention, a baffle means is provided intermediate the pumping chamber 14 and the discharge conduit 36 to cause the rotor pockets 18 to, during the rotation of the rotor 16, each initially open for only a minor part of their length to the discharge conduit 36 and thereafter open for a longer length to the latter. This baffle means moreover, as illustrated, is particularly constructed and arranged to cause each rotor pocket 18 to initially open to the discharge conduit 36 simultaneously with the commencement of the discharge of material from the rotor pocket 18 by the disc lobes 40 and also to cause the open length of the rotor pocket 18 to be gradually or progressively increased.

More particularly, as shown in FIGS. 1 and 2, this baffle means comprises an arcuate baffle 48 which also serves as a portion of the wall 46 of the pumping chamber 14 and has an edge 50, non-parallel to the walls bounding the sides of the rotor pockets 18, defining the side of the outlet 34 leading in the rotary direction of the rotor driven rotation. The edge 50 of the baffle 48 cooperates with the side wall 52 of the outlet 34 to cause the end portion 54 of the latter leading in the rotary direction of the rotor rotation to be of length (that is, dimension longitudinally of the rotor pockets 18) only a minor part of the length of each rotor pocket 18. The edge 50 is, moreover, particularly constructed to locate this leading portion 54 of the outlet 34 at a position whereby each rotor pocket opens thereto simultaneously with the initiation of the discharge of material from the rotor pocket 18 by a disc lobe 40. The edge 50 of the baffle 48 throughout its length gradually or progressively slopes away from the outlet side wall 52 in the rotary direction of the rotor rotation to cause the portions 56 of the outlet 34 trailing in such rotary direction to be of progressively increasing length (that is, dimension longitudinally of the rotor pockets l8) and hence longer than the outlet leading portion 54.

As will be understood, the employed baffle means does not need to be of the configuration of the aforedescribed baffle 48, but rather may alternatively be of other construction and arrangement suitable to cause the outlet 34 to, in the rotary direction of the rotor rotation, include a leading portion dimensioned to open to only a part of the length of each rotor pocket 18 followed by a trailing portion dimensioned to open to a longer length of each rotor pocket 18. For example, FIG. 3, wherein parts similar to those shown in FIGS. 1 and 2 are designed by the corresponding reference numeral followed by the suffix a, illustrates a modified baffle means in the form ofa baffle 4811 which is particularly constructed to cause the outlet 34a to extend the full length of the portion of the rotor 16a between the annular lands 24a and has an edge 50a including portions 58,60 of differing slope. Similarly, many other configurations of suitable baffle means may be readily constructed for the pump 10.

Due to the provision of the baffle means (whether it be in the form of the baffle 48, the baffle 48a or of other construction and arrangement), the driven rotation of the rotor 16 causes the rotor pockets 18 containing material received through the pumping chamber inlet 28 to be initially opened to the discharge conduit 36 through the outlet 34 for only minor parts of their lengths. Also, material is discharged from the rotor pockets l8 simultaneously with their opening to the outlet leading portion 54. Hence, in this manner the aforementioned vibration and hammering-type noise is substantially minimized; and material commences to be discharged from the rotor pickets l8 simultaneously with their opening to the outlet leading portion 54.

FIGS. 4 through 6 illustrate an embodiment of the invention in the form of a pump 62 which, generally considered, is of the character described in US. Pat. No. 3,001,481, issued Sept. 26, I96] and assigned to the assignee of the present invention. The pump 62 comprises a pump housing or casing 64 containing a pumping chamber 66 which, in turn, contains a pair of elon gated rotors 68, 70. One side of the pumping chamber 66 is provided with an inlet 72 communicating through an inlet conduit 74 with a source of the material to be pumped; the opposite side of the pumping chamber 66 is provided with an outlet, designated generally as 76, which is connected to a discharge conduit 78 arranged to convey the pumped materials to the desired location.

The rotors 68,70 are throughout the pump operation rotatably driven about their longitudinal axes in the opposite rotary directions schematically depicted by the arrows shown thereon in FIG. 4. The rotors 68,70 are of identical construction and each include a plurality of peripheral rotor pockets 80 along opposite sides bounded by the side walls 82 of the lobes 84 of the rotors 78,70. The pockets 80 longitudinally extend parallel to the axes of the rotors 68,70; and in the conventional manner the lobes 84 of each rotor 68,70 are received in the pockets 80 of the other thereof during an arcuate portion of the rotation of the rotors 68,70.

The baffle means employed in this embodiment of the invention is particularly constructed to cause the rotor pockets 80 of both rotors 68,70 to, during rotation of the latter, each initially open for only a minor part of their length to the discharge conduit 78 and thereafter open for a longer length to the latter. More particularly, this baffle means comprises identical arcuate baffles 86 for each rotor 68,70 both of which baffles 86 serve as portions of the wall 88 of the pumping chamber 66. The baffles 86 each have an edge 90, nonparallel to the walls 82 bounding the sides of the rotor pockets 80, defining the side of the outlet 76 leading in the rotary direction of the driven rotation of the corresponding rotor 68,70. The edge 90 of each baffle 86 causes the outlet 76 to include a centrally located end portion 92 (that is, as shown in FIG. 6, an end portion 92 located centrally of the corresponding rotor and its rotor pockets), leading in the rotary direction of the driven rotation of the corresponding rotor, which is of length (that is, dimension longitudinally of the rotor pockets 80 of the rotor 68,70) only a minor part of the length of the rotor pockets 80. The edge 90 of each baffle 86 is, moreover, particularly constructed to cause the portions 94 of the outlet 76 trailing such leading portion 92 to be of gradually or progressively increasing length; and intermediate the baffles 86, the outlet 76 includes a portion 96 extending the full length of the rotor pockets 80.

The operation of the pump 62 is believed to be apparent in view of the aforegiven description of the operation of the pump 10. More particularly, during the operation of the pump 62 the rotors 68,70 are continuously rotatably driven in the respective rotary directions schematically shown by the arrows in FIG. 4 to alternately connect their rotor pockets 80 with the pumping chamber inlet 72 and outlet 76. The pockets 80 of both rotors 68,70 each initially communicate with the corresponding leading portions 92 of the out let 76, thereby providing the aforedescribed benefits attained by the invention, and subsequently communicate with the outlet trailing and full length portions 94,96 through which material is discharged from the rotor pockets 80.

The battle means of the pump 62, of course, need not be of the configuration of the baffles 86 illustrated in FIGS. 4 through 6 but rather may alternatively be of other suitableconstruction and arrangement. For example, FIG. 7,.wherein parts corresponding to those shown in FllGS. 4 through 6 are designated by the reference character for the aforedescribed similar part followed by the suffix a, illustrates one suitable alternative form of baffle means; and FIG. 8, wherein parts corresponding to those shown in FIGS. 4 through 6 are designated by the reference character for the aforedescribed similar part followed by the suffix b, illustrates another suitable alternative form of baffle means. As will be noted, the FIG. 8 embodiment of the baffle means is different from all of the other illustrated baffle means in that the baffles 86b do not cause the outlet to be of gradually or progressively increasing length, and the edges 90b of the baffles 86b include portions parallel to the sides of the rotor pockets. Also, as will be seen from FIGS. 6 and 8, the baffles 86, 86b cause the therein shown outlets to be of cruciform or cross-like configuration.

From the preceding description it will be seen that the invention provides new and improved means for attaining all of the aforestated objects and advantages. It will be understood, however, that, although only a few embodiments of the invention have been illustrated and hereinbefore specifically described, the invention is not limited merely to these few embodiments but rather contemplates other embodiments and variations within the scope of the following claims.

Having thus described my invention, I claim:

1. A pump comprising a housing containing a pumping chamber having an inlet and an outlet; a rotor in said pumping chamber provided with a plurality of peripheral rotor pockets and rotatable in a predetermined rotary direction to open said rotorpockets to said inlet and said outlet, alternately; and baffle means operatively associated with said outlet for causing said outlet to, in said predetermined rotary direction, include a leading end portion centrally of said rotor pockets and of dimension longitudinally of said rotor pockets only a minor part of the length of each said rotor pocket followed by a trailing portion of greater dimension longitudinally of said rotor pockets than said leading end portion whereby, during rotation of said rotor means in said predetermined rotary direction, each said rotor pocket opens first to said centrally located leading end portion of said outlet and thereafter to said trailing portion thereof.

2. A pump according to claim ll, wherein said outlet progressively increases in dimension longitudinally of said rotor in said predetermined rotor direction.

3. A pump according to claim I, wherein said outlet includes a portion which extends the full length of said rotor pockets.

4. A pump according to claim I, wherein said outlet progressively increases in dimension longitudinally of said rotor in said predetermined rotary direction, and said outlet includes a portion which extends the full length of said rotor pockets.

5. A pump according to claim I, further comprising a second rotor in said pumping chamber; said second rotor being provided with a pluralltiy of peripheral sec ond rotor pockets and being rotatable in a second pre determined rotary direction opposite to said first pre determined rotary direction to open said second rotor pockets to said inlet and said outlet, alternately; and said baffle means causing said outlet to, in said second predetermined rotary direction, include a leading end portion centrally of said rotor pockets and of dimension longitudinally of said rotor pockets only a minor portion of the length of each said second rotor pocket followed by a trailing portion of greater dimension lon gitudinally of said rotor pockets than said leading end portion whereby, during rotation of said second rotor means in said second predetermined rotary direction, each of said second rotor pockets opens first to each centrally located leading end portion of said outlet and thereafter to such trailing portion thereof.

6. A pump according to claim S, wherein said outlet is of cruciform configuration.

7. A pump according to claim .5, wherein said outlet progressively increases in dimension longitudinally of said rotor in each said rotary direction.

8. A pump according to claim 5, wherein said outlet I intermediate said leading end portions includes a full length portion extending the full length of said rotor pockets.

9. A pump according to claim 5, wherein said outlet progressively increases in dimension longitudinally of said rotor in each said rotary direction, and said outlet intermediate said leading end portions includes a full length portion extending the full length of said rotor pockets.

[0. A pump comprising a housing containing a pump ing chamber having an inlet and an outlet; rotor means in said pumping chamber provided with a plurality of peripheral rotor pockets and rotatable in a predetermined rotary direction to cause said rotor pockets to be opened to said inlet and said outlet, alternately; and baffle means causing said outlet to, in said predetermined rotary direction, include a leading end portion centrally of said rotor pockets dimensioned to open to only a minor part of the length of each said rotor pocket followed by a trailing portion dimensioned to open to a longer length of each said rotor pocket.

11. A pump according to claim 10, wherein said baffle means causes said outlet to be of progressively increasing dimension in said predetermined rotary direction.

12. A pump according to claim 10, further comprising second rotor means in said pumping chamber provided with a plurality of peripheral second rotor pockets and rotatable in a predetermined rotary direction to cause said second rotor pockets to be opened to said inlet and said outlet, alternately; said baffle means causing said outlet to, in said predetennined rotary direction of said second rotor means, include a leading end portion centrally of said rotor pockets dimensioned to open to only a part of the length of each said second rotor pocket followed by a trailing portion dimensioned to open to a longer length of each said second rotor 16. A pump according to claim 12, wherein said out let intermediate said leading end portions includes a portion extending the full length of said rotor pockets 

1. A pump comprising a housing containing a pumping chamber having an inlet and an outlet; a rotor in said pumping chamber provided with a plurality of peripheral rotor pockets and rotatable in a predetermined rotary direction to open said rotor pockets to said inlet and said outlet, alternately; and baffle means operatively associated with said outlet for causing said outlet to, in said predetermined rotary direction, include a leading end portion centrally of said rotor pockets and of dimension longitudinally of said rotor pockets only a minor part of the length of each said rotor pocket followed by a trailing portion of greater dimension longitudinally of said rotor pockets than said leading end portion whereby, during rotation of said rotor means in said predetermined rotary direction, each said rotor pocket opens first to said centrally located leading end portion of said outlet and thereafter to said trailing portion thereof.
 2. A pump according to claim 1, wherein said outlet progressively increases in dimension longitudinally of said rotor in said predetermined rotor direction.
 3. A pump according to claim 1, wherein said outlet includes a portion which extends the full length of said rotor pockets.
 4. A pump according to claim 1, wherein said outlet progressively increases in dimension longitudinally of said rotor in said predetermined rotary direction, and said outlet includes a portion which extends the full length of said rotor pockets.
 5. A pump according to claim 1, further comprising a second rotor in said pumping chamber; said second rotor being provided with a pluraltiy of peripheral second rotor pockets and being rotatable in a second predetermined rotary direction opposite to said first predetermined rotary direction to open said second rotor pockets to said inlet and said outlet, alternately; and said baffle means causing said outlet to, in said second predetermined rotary direction, include a leading end portion centrally of said rotor pockets and of dimension longitudinally of said rotor pockets only a minor portion of the length of each said second rotor pocket followed by a trailing portion of greater dimension longitudinally of said rotor pockets than said leading end portion whereby, during rotation of said second rotor means in said second predetermined rotary direction, each of said second rotor pockets opens first to each centrally located leading end portion of said outlet and thereafter to such trailing portion thereof.
 6. A pump according to claim 5, wherein said outlet is of cruciform configuration.
 7. A pump according to claim 5, wherein said outlet progressively increases in dimension longitudinally of said rotor in each said rotary direction.
 8. A pump according to claim 5, wherein said outlet intermediate said leading end portions includes a full length portion extending the full length of said rotor pockets.
 9. A pump according to claim 5, wherein said outlet progressively increases in dimension longitudinally of said rotor in each said rotary direction, and said outlet intermediate said leading end portions includes a full length portion extending the full length of said rotor pockets.
 10. A pump comprising a housing containing a pumping chamber having an inlet and an outlet; rotor means in said pumping chamber provided with a plurality of peripheral rotor pockets and rotatable in a predetermined rotary direction to cause said rotor pockets to be opened to said inlet and said outlet, alternately; and baffle means causing said outlet to, in said predetermined rotary direction, include a leading end portion centrally of said rotor pockets dimensioned to open to only a minor part of the length of each said rotor pocket followed by a trailing portion dimensioned to open to a longer length of each said rotor pocket.
 11. A pump according to claim 10, wherein said baffle means causes said outlet to be of progressively increasing dimension in said predetermined rotary direction.
 12. A pump according to claim 10, further comprising second rotor means in said pumping chamber provided with a plurality of peripheral second rotor pockets and rotatable in a predetermined rotary direction to cause said second rotor pockets to be opened to said inlet and said outlet, alternately; said baffle means causing said outlet to, in said predetermined rotary direction of said second rotor means, include a leading end portion centrally of said rotor pockets dimensioned to open to only a part of the length of each said second rotor pocket followed by a trailing portion dimensioned to open to a longer length of each said second rotor pocket.
 13. A pump according to claim 12, wherein said baffle means causes said outlet to be of progressively increasing dimension in both said predetermined rotary directions.
 14. A pump according to claim 12, wherein said baffle means causes said outlet to be of cruciform configuration.
 15. A pump according to claim 12, wherein said outlet progressively increases in dimension longitudinally of said rotor in each said rotary direction, and said outlet intermediate said leading end portions includes a full length portion extending the full length of said rotor pockets.
 16. A pump according to claim 12, wherein said outlet intermediate said leading end portions includes a portion extending the full length of said rotor pockets. 